As technology progresses, the manufacturing technique of monitor display is also progressing. Following the technique of light emitting diodes (LEDs), the newest technique of monitor display brought to the market is one that utilizes organic light emitting diodes (OLEDs). Each OLED requires a driver circuit to drive it for emitting light. The light can be of either a single color, such as red, green, blue, or full colors. The advantages of OLEDs are the flexibility, liberation from viewing angle restriction, long product lifetime and low power consumption. Accordingly, OLEDs are very likely to replace LEDs and become the most popular monitor display in the next generation.
Each pixel of an AMOLED needs an OLED and a driver circuit so there are ten thousands or even millions of driver circuits in one panel. It is a complicated task to conclude the functionality of all driver circuits in one panel. FIG. 1 shows one common driver circuit configured to drive an OLED of a monitor display. Referring to FIG. 1, the method of prior art for testing the driver circuit starts with enabling it via the scan line SL and inputting a certain voltage level via the data line DL after an OLED D1 is implanted. The driver circuit then transfers the voltage level into a current signal I which makes the OLED D1 emit light. According to the voltage level, test engineers determine the D1's functionality by subjectively observing its luminosity with eyes. If there is a failure in the tested driver circuit, the OLED D1 having been implanted in it is wasted and cannot be recovered even though the OLED D1 itself is still good. Accordingly, this test method of prior art would result in not only imprecision caused by the test engineers' subjective decision but also high costs.